import java.util.*;
import java.io.*;

public class Main {
    public static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
    public static Read in = new Read();

    public static void main(String[] args) {
        HashMap<Integer,Integer> map = new HashMap<>();
        System.out.println("Hello world!");
        out.println("hello world");
    }
}

class Read {
    StringTokenizer st = new StringTokenizer("");

    BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));

    String next() throws IOException {
        while(!st.hasMoreTokens()) {
            st = new StringTokenizer(bf.readLine());
        }
        return st.nextToken();
    }

    String nextLine() throws IOException{
        return bf.readLine();
    }

    int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }
}